1. Field of the Invention
This invention relates to a sheet post-handling device for taking in and storing sheets fed from an image forming apparatus such as a copying machine, and more particularly to a device for stably stacking sheets which are aligned and bound on a tray in a sheet storage section.
2. Description of the Prior Art
Sheet handling devices for automatically sorting, aligning, binding and storing recorded sheets continuously fed from an image forming apparatus such as a copying machine, printer, and facsimile have been used.
A conventional sheet post-handling device of this type has been known, in which sheets continuously fed from the image forming apparatus are sorted and distributed into bin trays to form sheaves of sheets in the bin trays, and then, the sheaves of sheets are bound with staples as occasion calls. One example of the conventional sheet post-handling devices is disclosed in Japanese Patent Application Public Disclosure No. 6-9142(A). The conventional device comprises a sheet processing section for binding sheets continuously fed from the image forming apparatus into a sheaf of sheets, and a sheet storing section for stacking the sheaf of bound sheets, which sections are placed side by side.
In the aforenoted conventional sheet post-handling device, the sheets continuously fed from the image forming apparatus are sent one by one into a first tray in a sheet processing section, aligned and bound into a sheaf of sheets and then, transferred to a second tray in a sheet storing section by use of sheet transferring means. The sheaves of sheets bound stored in the sheet storing section in order can be freely taken out. This sheet post-handling device has no need for multistage bin trays and a system for controlling the bin trays, and thus, can be made relatively simple in structure and small in size.
In the aforementioned conventional post-handling device employing stationary rollers for transferring the sheaf of sheets from the first tray to the second tray, as a matter of course, the second tray is placed lower in level than the first tray in order to transfer the sheaf of sheets from the first tray to the second tray without a hitch. When the sheaf of bound sheets is transferred from the first tray to the second tray by use of the stationary transferring rollers disposed above the second tray, the sheaf of sheets released from the stationary rollers falls to the second tray. As a result, the sheaves of sheets successively sent into the sheet storing section and falling to the second tray are accumulated in disarray on the second tray. Especially, the disarray of the sheaves of bound sheets on the second tray becomes conspicuous with elevating the operation speed at which the sheets are sent. Ultimately, the conventional device disadvantageously calls for the onerous work of tidying up the sheaves of sheets stacked in disarray on the second tray afterward, and further entails the risk of damaging the sheaf of bound sheets.
An object of the present invention is to provide a sheet post-handling device capable of efficiently aligning and binding sheets continuously fed from an image forming apparatus such as a copying machine into one or more sheaves of bound sheets, reliably transferring the sheaves of sheets to a sheet storing section, and accumulating and storing the sheaves of sheets in order in the sheet storing section.
Another object of the present invention is to provide a sheet post-handling device capable of stably transferring and storing the sheaf of sheets aligned and bound without imposing a burden on the sheets.
Still another object of the present invention is to provide a sheet post-handling device easy to handle and diminished in size, which is capable of performing after-processing for handling the sheets at a high speed without retarding the image forming apparatus operable at a high speed.
To attain the objects described above according to the present invention, there is provided a sheet post-handling device comprising a first tray for stacking one or more sheets thereon, means for transferring the aforesaid one or more sheets stacked on the first tray while holding the sheets, a second tray for stacking the sheets sent from the first tray by the transferring means, means for gripping the sheets arriving at the second tray, means for moving the gripping means along the surface of the second tray, and means for tilting vertically the gripping means located at a sheet releasing position in the second tray.
The sheets fed onto the first tray are aligned by sheet aligning means and bound with a staple or staples into a sheaf of sheets while being transferred from the first tray to the second tray.
The sheaf of sheets thus aligned and bound is sent toward the second tray by the transferring means and passed to the gripping means at the second tray.
When the sheaf of sheets gripped by the gripping means arrives at a prescribed position just over the second tray while the gripping means reaches the sheet releasing position, the gripping means is tilted downward to bring the gripped sheets close to the second tray, and then, releases the gripped sheets. Thus, the sheaf of sheets can be softly landed on the second tray.
When a plurality of sheaves of sheets are consecutively sent to and accumulated on the second tray, the second tray is moved downward in accordance with the thickness of the sheaves of sheets stacked thereon.
When putting the sheaves of bound sheets on the second tray, it is desirable to displace alternately the sheaves of sheets slightly in direction in which the sheets are transferred, so as not to place the stapled portions of the sheets with staples on top of another. As a result, the bulk of the sheaves of sheets accumulated on the second tray can be reduced.
Other objects and features of the present invention will be hereinafter explained in detail with reference to the accompanying drawings.